The earlier drilled wheat and barley is now through and looks well, with slugs being the biggest problem. Soil type maps are generally used to target high risk slug areas and patch treated where appropriate to reduce the amount of metaldehyde being used. It is also worth reminding growers of the 210g/ha metaldehyde stewardship limit.
Residual pre-emergence herbicides should be performing well with the recent wet weather but in some earlier drilled fields blackgrass is already emerging!
Most of the early drilled wheat was Deter (clothianidin) treated to provide approximately six weeks aphid protection. After the six week period and where Deter was not used, a post-emergence aphicide is likely to be required if conditions remain mild to prevent barley yellow dwarf virus (BYDV). Day degrees post crop emergence and information from aphid suction traps can be used to determine aphid pressure and the best timing for application.
The worst blackgrass fields are due to be drilled this week and next week, with the rain at the end of September helping to break down cloddy seed-beds and stimulate further flushes of blackgrass.
August drilled oilseed rape continues to grow away well even in the cabbage stem flea beetle (CSFB) hotspot areas of last year, with some fairly large canopies to manage. Later drilled crops are slowly catching up, but have been very slow and suffered more from damage, although recent activity seems to have declined in the cooler nights and as they start to lay eggs.
With phoma being found in crops last week and Rothamstead predicting that the 10% threshold had been reached, most crops will have received a fungicide this week. Also, Myzus persicae numbers were still relatively low at the time of writing, reducing the potential risk of TuYV.
This season has seen a much larger area of Clearfield rape being planted to overcome troublesome weeds like charlock, runch and hedge mustard, whilst also giving us a reliable post-emergence broad-leaved herbicide. The Cleranda (imazamox + metazachlor) has been applied and has done a fantastic job of controlling the problem weeds, but the most impressive part has been the Clearfields rapid establishment. Up until the 2-leaf stage, the development of the Clearfield and non-Clearfield varieties were comparable, but beyond this the Clearfield has been quicker to develop than the others.
The additional benefit of Clearifeld is its tolerance to ALS-inhibiting herbicide residues from sulfonylurea products like Atlantis and spring broad-leaved weed killers. Many non-Clearfield varieties seem to get to cotyledon/1-leaf and are then slow to develop until they have 3-4 leaves on them and the roots are deeper. However, the Clearfield OSR seemed to keep growing through this period and have developed quicker than the other varieties. Where we are doing less soil disturbance and less mixing of the soil this could be something else to consider when trying to get the crop established quickly.
Winter beans are due to be drilled in the later part of October and ensure seed is tested for thousand grain weight, germination, ascochyta and stem nematode. If any stem nematode are found then the seed should not be used. Where blackgrass is a concern in winter beans, the seed-bed should be left as fine as possible, which may mean an additional pass with a cultivator. This will help with the residual herbicide. Also, do not drill too early as if Kerb (propyzamide) is being used as part of the blackgrass control programme soil temperatures ideally want to be 10C and falling at 30cm depth.
Spring crop land has received two or three glyphosate applications with brome and blackgrass readily germinating on the surface. A final deep cultivation will be made prior to the winter and the land then left to weather and green up over the winter.